


"Can I Borrow An Eraser?"

by Its_Raining_Here



Category: Undertale (Video Game)
Genre: Adorable Papyrus (Undertale), Alphys is crushing hardcore, Alternate Universe - High School, F/M, First Kiss, Fluff, Gaster has a tiny crush on the king, Good W. D. Gaster, Papyrus is 11, Papyrus is the Best (Undertale), Parent W. D. Gaster, Sans and Alphys are 15, Sans is oblivious AF, Swearing, WingMan Gaster, thats the only reason this is rated T
Language: English
Status: Completed
Published: 2020-11-16
Updated: 2020-11-16
Packaged: 2021-03-09 22:53:37
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,797
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27583666
Author URL: https://archiveofourown.org/users/Its_Raining_Here/pseuds/Its_Raining_Here
Summary: Sans and Alphys go to school together, and Alphys is crushing on him hardcore. He has no idea. Papyrus and Gaster are there to help though.
Relationships: Gaster/Asgore (Implied), Sans/Alphys
Comments: 14
Kudos: 30





	"Can I Borrow An Eraser?"

**Author's Note:**

> I just kinda sat down and wrote this today. Not proofread, let me know if there are any typos.
> 
> (just changed rating to T for light swearing)

“can i borrow an eraser?” 

Alphys jumped, not expecting anyone to be next to her. She whipped her head to the left, and stared at the new monster.

“ah, jeez, sorry. didn’t mean to scare ya outta your scales.” the monster muttered apologetically.

Alphys took a moment to collect herself, before speaking.

“O-oh, it’s n-no problem! I j-just wasn't e-expecting anyone t-to be there.” She hurried to reassure him.

He chuckled.

“still, sorry for sneakin up on ya like that. i seem to just pop out of nowhere sometimes.”

Alphys smiled.

“It’s a-alright. Here, y-you asked for an e-eraser, right?”

She dug around in her Mew Mew Kissy Cutie pencil case, and pulled out a small kneaded eraser.

“thanks, you’re a lifesaver.” He turned to sit back down at his desk, before stopping.

“when do you need this back? i don’t wanna steal your stuff on accident.”

She waved him off.

“Nah, y-you can k-keep it. I’ve got m-more erasers.”

“sweet, thanks again.”

He walked back to his desk, in the corner of the classroom by the window. Alphys kept her gaze on him for a moment longer. He looked like an anime protagonist. Wearing a soft blue hoodie with white fur on the hood, and light grey turtleneck sweater. Large round glasses taped to the side of his skull. Long black sweatpants loosely covering his short legs, fabric spilling onto his pink slippers. 

How he got away with slippers in school, Alphys wasn’t sure. 

Her daydreaming went on for a bit longer than intended, when she heard the teacher call her.

“Alphys, eyes on your work!”

“S-sorry Mr. Gaster!” 

Class was rather uneventful after that, as if anything could compare to her meeting with the unnamed monster. All he had done was ask for an eraser, and Alphys screwed up her first impression. 

School had been in session for a few months now, so it was strange that Alphys hadn’t noticed him yet. He did sit in the back corner, though, maybe he wanted to go unseen? While typing up her essay, Alphys found herself fantasizing about the skeleton monster. 

_Maybe he’ll talk to me again at lunch, and we’ll slowly become close friends. Soon after, we develop strong feelings for one another. Then he invites me to meet under a cherry blossom tree. He confesses his undying love for me and I accept immediately with tears in my eyes. He’ll scoop me up in his strong arms, and carry me away into the sunset. We stick together through the rest of school, get married, and have 3 adorable childr-_

_Oh my god I typed all of that on my essay._

She started quickly deleting what she had typed, when her hand was pulled away from the keyboard.

“hold on, lemme finish reading. he confesses his undying lov-”

Alphys shrieked. Loudly.

“Oh my g-god please t-tell me y-you weren’t t-there the w-whole t-t-time!” Alphys swiftly erased the remains of her dreaming, and buried her head in her sleeves.

“hey, calm down. s’no biggie. so, you like to write fanfic, huh? at least, i’m guessing that’s what you were doing”

Alphys lifted her head a little, not making eye contact with him.

“Y-yeah...it’s w-weird, I know.” She mumbled.

He looked a bit confused at that.

“well, i don’t think it’s weird. if it makes you happy, and it's not hurting anyone, what’s the problem?”

He sat down next to her, setting down his backpack on the bench. 

“if it makes you feel better, i write fanfic sometimes. it’s a good way to pass the time, and stretch my figurative creative muscles.”

She glanced up at him. 

“R-really?”

“hehe, yup. it’s kinda fun to take these cool characters and make em do random shit.”

She raised her head all the way up again, rubbing her eyes.

“I-I’m so s-sorry. I’m n-not usually that j-jumpy.”

“is that right?” He looked amused.

Alphys huffed.

“Pfft, you jerk.”

He chuckled a bit.

“that reminds me, i don’t think we’ve properly introduced ourselves.”

“O-oh! Right, s-sorry. I’m Alphys .” She held out her hand.

“comic sans serif gaster. a mouthful, i know.” He shook her hand, looking to the side.

“Oh! Are y-you related to Mr. G-Gaster?” She looked amazed.

“yeah, he’s my dad, actually. kinda embarrassing though, he doesn’t really let me do anything.”

Alphys deflated.

“O-oh, I’m sorry.”

Sans shrugged.

“s’all right, he’s just overprotective i guess.”

“Well, at l-least it s-shows he c-cares about you.”

“eh, i suppose. can’t remember the last time i went to a friends house. he never lets me outside unless he goes with me.”

She looked puzzled.

“Okay, t-that’s pretty e-exessive. N-no offense.”

“none taken.”

Alphys fidgeted with her claws.

“C-can I ask w-why he’s l-like that?”

“s’just cause i’m really weak. like, my stats are shit.”

She huffed again.

“Oh, I-I’m sure they’re not t-that bad!” 

Alphys turned back to her laptop, and resumed her typing.

He stared at her, his face blank.

“check me.”

She stared back. 

“W-what?”

“check me.” He repeated. “you said my stats can’t be that bad, i’m here to prove you wrong.”

Hesitantly, Alphys checked Sans’ soul.

SANS  
HP: 1/1  
ATK: 1  
DEF: 1  
Smells like ketchup.

Her eyes widened when she saw his stats.

“O-one HP?! W-w-what?!” Alphys stuttered.

“heh, yep. i’m weaker than most toddlers. pretty funny, right?” Sans didn’t seem as worried as he should be.

“N-no, I d-don’t think it’s v-very funny. You c-could die a-at any m-moment!”

“so can everyone else. who’s to say a piano won’t fall from the sky and land on us? that would kill me, but it would also kill any other monster.” He reasoned.

“I d-don’t think t-that makes it a-any be-”

She was interrupted by the voice of their teacher.

“Sans! There you are!” Gaster sprinted over to them, looking worried.

His eyelights darted over Sans, searching for any injuries. Gaster towered over the two, due to his height.

“heya dad, how's the weather up there?”

“Sans, this is no time for jokes! Are you okay? You scared me to death, sneaking off like that!” Gaster planted his hands on Sans’ shoulders, shaking him lightly.

“m’fine dad, you worry too much. just wanted to try to make some friends. it gets bonely when you don’t have anyone to spend lunch break with.

Gaster sighed, and continued.

“We can’t risk you getting hurt. If you want to wander around, inform me first, and I will accompany you.”

Sans glared at him.

“see, that’s the problem. no one wants to be friends with the kid whose dad follows him everywhere.” He retorted.

He looked over to Alphys.

“sorry about this, c’mon dad, let’s just go.”

Sans stood up, and Gaster reached out for his hand. Sans took it and they started to walk away. 

He looked back at Alphys over his shoulder and smiled.

Alphys smiled back, and waved.

——————

Over the course of the next few weeks, Alphys found herself staring at Sans in class more often. It was a bit more obvious than she would have liked, with him sitting in the back corner and all, but he didn’t seem to notice.

Surprisingly, Sans still came by everyday to sit with Alphys for lunch. Gaster was there too now, but he mostly observed, carefully watching Sans from a distance. Sans had somehow convinced Gaster to let him be partially alone, even if only for half an hour. The other students glanced over to them sometimes, whispering to each other about anything the two did, but they didn’t care. They were having fun.

One day, Sans and Gaster came by the small lunch table where they always sat. Alphys was already there, typing away on her laptop, and eating dry ramen.

“heya al. whatcha doin?” 

“O-oh, hi Sans! I’m j-just doing s-some school work.” She turned her head to face them.

Sans hummed, and sat down next to Alphys. Gaster sat on the other side of the table, rather than his usual spot underneath a tree. 

Sans dug around in his backpack for a moment, before pulling out a sandwich. He tore off the plastic wrap and began eating.

“W-what kind of sandwich is that?” Alphys asked.

“i call it the sanswich. s’just ketchup and bread.” 

“Oh my g-god, how can you e-eat that?” Alphys giggled.

_*Munch*_

“it tastes good. i don’t get how you can eat that stuff dry.” 

“A-at least mine i-is actual f-food.” 

“hey! the bread is real food. s’made with the same stuff as your dry ass noodles. nothin but wheat flour and salt.”

“Language, Sans. This is a school.” Gaster scolded. 

“a’right.”

He took another bite from his sanswich. 

”hey alphys, i meant to ask you, _*munch*_ didja wanna come over to my place after school? _*munch*_ we can play video games and eat junk food till we pass out.” He said in between bites.

“I would hope not Sans, you have homework.”

“okay, we can play video games after homework. you in?”

Alphys beamed.

“Y-yeah! That s-sounds like a lot o-of fun! I’ll t-text my p-parents and l-let them know.”

She pulled out her phone and tapped away, claws clicking on the screen.

“They s-said I c-can go. What t-time should I h-head over?” Alphys asked.

“you can just walk home with us. unless you wanna go home first and get anything.” Sans responded.

“I-I’ll go with y-you guys.” She texted her mom as such, and put her phone away.

“great. when class ends, just walk out with us. maybe we can get some nice cream on the way?” Sans looked at his dad, waiting for an answer.

“I don’t see why not. You’ve both been doing well in class, I suppose some nice cream would be a suitable reward.” Gaster replied with a small smile.

“Yes!” “yes!” Alphys and Sans shouted in unison. They looked at each other and laughed. 

Gaster chuckled, and the other two continued eating their lunch, talking about nothing in particular.

——————

The loud ring of the school bell filled the halls, and Alphys began scrambling to gather her things. 

Sans, who had been dozing off, awoke with a jolt and shook his desk with the sudden movement.

The rest of the students in the room hurried to leave, eager to leave school as soon as possible. Some leaving behind pens, or a notebook in their rush. Gaster sighed and collected all the lost materials, and placed them in a Lost and Found bin.

Sans walked over to Alphys, his black backpack slung lazily over his shoulder. She was zipping up her bag when she noticed him next to her.

“S-sorry, I’m a-almost done. J-just one s-second.” She apologized.

“nah, take your time. s’all good.” He reassured her.

Gaster was turning off his computer, and putting away stray books when the two approached him, waiting for him to finish.

“I wish these people would at least clean up after themselves. These books are expensive.” Gaster muttered, half to himself.

“well, most of the kids here are filthy rich. so they can afford to be destructive. what do you expect?” Sans joked.

“I would expect them to understand the value of money, Sans.” 

“fair point.” 

Sans helped his dad clean up the last bits of the classroom, before they were ready to go.

“a’right, ready alph?”

“Y-yep! Let’s g-go!” 

“Then we’re off.” Gaster walked out of the classroom, holding his son's hand the whole way.

Alphys thought it was kind of cute, how much he cared for Sans. Even if it annoyed him, Sans was lucky to have someone who loved him that much. Her parents weren’t abusive, just a bit too laid back. They never really stopped Alphys from doing anything, even if it hurt her. 

Alphys wished her parents were a bit more like Gaster.

They passed by the nice cream stand, and bought 3 cones. Sans got chocolate, Alphys got matcha, and Gaster got a cone of vanilla, and a small container of strawberry.

“i bet you’ll love my brother, papyrus. everyone does.” Sans spoke, breaking the short silence.

“Y-you have a brother? I-I didn’t e-even know th-that.”

“You never told her about Papyrus? He’s literally the one thing you never shut up about.” Gaster teased.

“i guess he just never came up in conversation.” Admitted Sans.

“Unbelievable. You would snag any chance to ramble about him.”

“C-can you tell m-me about him?” Alphys asked. She wanted to know more about the mystery skeleton brother she didn't know existed until now.

Sans had told her that Papyrus is the coolest monster ever, and that no one can compare, not even King Asgore. Gaster seemed to blush a bit at the mention of the King. She would have to do some further exploration on that topic another time. Papyrus was apparently only in 5th grade, but he was top of his classes, especially in PE. 

“he’s really fast, and really strong!” Sans said. “and he’s a pretty good cook on top of that.”

“He s-sounds like a r-really cool kid! I c-can’t wait to m-meet him.” 

“you’ll love him alphy, he’s the best!”

The pair continued to talk about various topics, with Gaster occasionally adding to the conversation. Eventually, they arrived at the house.

It was a nice two story, with golden flowers planted outside every window. It was painted a light blue, and the roof was a nice brown color. There was a small stone path leading up to the front door, where a wreath of flowers was hung on the door window.

“W-woah! Your h-house is really p-pretty!”

“dad is the one who did all this, thank him for making it look nice. if it were up to me, i would’ve painted it to look like space, and it wouldn’t look all that cool, cause i can’t paint.” Sans explained.

“It was your idea to put the path there, you helped.” Said Gaster.

“yeah but the flowers pull everything together. that was your idea, so you did most of it.”

Sans seems adamant on the fact that he didn’t do anything for the house, it’s almost adorable how he shifts everything to Gaster.

_Oh my god I think he’s adorable._

Gaster walked Sans to the door, still holding his hand tightly. Alphys shyly followed, feeling a bit out of place. Gaster fumbled with a keychain in his free hand, and unlocked the door. Walking in, he shouted.

“Papyrus! We’re home!” Gaster called.

A small skeleton bounded down the stairs with a huge smile on his face, almost tripping on the steps. He ran over to Gaster and jumped on him. 

“Dad! Sans! Mystery Person! Welcome home!” Papyrus yelled excitedly.

“heya pap. this is alphys, alphys, this is papyrus. alph is gonna hang with us today.” Sans introduced the two.

“H-hello!” Alphys held out her hand.

“Hello! Good to meet you Alphys!” Papyrus shook her hand swiftly.

“Y-you too, Papyrus.”

“We went to get some nice cream on the way home, so I got you some strawberry, Papyrus.” Gaster said

Papyrus gasped.

“Really?! Thank you dad!” Papyrus squealed.

“You may have it when you finish your homework, alright? I’ll put it in the freezer for now.”

“Okay! That homework wont know what hit it!” 

Papyrus sprinted back upstairs and almost ran face first into his door, before turning around and shouting.

“Be nice to my brother Alphys! He’s not strong like me!”

“G-gotcha.”

He turned back and walked into his room, closing the door behind him with a soft click.

“You two need to do your homework as well.” Gaster turned to Sans and Alphys.

“got it dad, let’s go up to my room alph!” Sans started walking up the stairs as well, and Alphys followed close behind.

“I’ll bring you two some snacks later, alright?” 

“sounds good, thanks dad!” 

“T-thank you Mr. G-Gaster.”

The pair walked down the hall and came to a stop at a door with a sign on it. The sign read:

_Sans’ Evil Lair_  
DO NOT ENTER UNLESS YOU HAVE KETCHUP  
i also take chocolate as an offering. 

“I l-like your sign. It’s f-funny.” 

_Oh my god Alphys put some emotion into your words._

“thanks, made it myself.” He turned the doorknob and pulled out a ketchup packet from his pocket. “don’t worry about the warning, i always keep ketchup on hand.”

“Pfffft. You’re a-always prepared, huh?” Alphys teased.

“yep, never know when you’re gonna need a quick snack.”

Sans walked into his room, and Alphys stared at the sight of it. 

The walls were painted with stars of every size on a dark blue background. Sci-Fi movie and book posters were hung all over the room, covering the wall where stars did not. The floor was a soft carpet, similar to the rest of the house. His bed had a big, soft looking blanket that was also covered in star patterns.

“W-wow. Y-your room i-is way cooler th-than I thought it would b-be. Oh, n-not that I thought i-it would be n-not cool, I knew i-it would be c-cool, I just-” 

“s’okay alph, don’t worry bout it. i know whatcha meant. i’m not the most interesting person, haha.” Sans chuckled. 

“anyways, you can just throw your stuff wherever, then we can do our homework like losers.”

“Y-yeah! Let’s be the b-biggest losers!” 

“that’s the spirit.”

\------------------------

About half an hour later, while the pair was working on their math homework, there was a knock on the door. Without looking up from his paper, Sans half shouted.

“don’t gotta knock, dad. come in.”

The door cracked open, and Gaster poked his head in. 

“Just making sure I wasn’t interrupting anything.” He said with a wide, shit eating grin on his face.

Alphys turned bright red, and buried her face in her paper, while Sans rolled his eye lights.

“s’just homework dad. nothin’ to interrupt.”

_Holy crap he’s completely oblivious thank god._

Gaster sighed, and walked fully into the room, carrying a plate. There was a small pile of chips, a few strawberries, and a handful of marshmallows. He set the plate down in between the pair.

“I didn’t know what snacks you liked, Alphys, so I just put some of the basics. Oh, and here, Sans. I didn’t forget this time.” Gaster pulled a bottle of ketchup from his jacket pocket.

Alphys swore she could see Sans’ eye lights morph into small stars.

“oh sweet! it’s even the spicy one, thanks dad!” Sans immediately popped the cap open and took a “sip” (?) 

“It’s s-still hard to b-believe that you j-just drink it like th-that”

“it’s a great snack. want some?” He took a small ketchup packet from his pocket.

“I-I mean...sure?” Alphys took the packet and tore off a corner, holding it up to her mouth. 

It wasnt... bad. Not an amazing food, but she didn’t hate it. 

“I-it’s not that b-bad, I guess.” 

“s’my favorite. chocolate is right behind it on the favorite food list.”

“W-well, now I know w-what to get y-you for your b-birthday.” Alphys giggled.

“I can’t believe you, Sans, you’re going to infect the poor girl with your condiment obsession.” Gaster smacked Sans’ forehead lightly.

“aw, don’t be so salty.”

“I don’t have to listen to your food puns right now. Have a fun time with my disappointment of a son.” Gaster turned to walk out the door.

“S-sure thing, Mr. Gaster!”

Sans laughed at that.

“gee, love you guys too.”

Gaster left without responding, but the pair could hear him stifle a laugh.

Smiling, Sans looked over at Alphys. And dear god she could get lost in his eye sockets. Endless black voids, lit only by large, round eyelights. He was adorable.

She could never say that to his face, obviously.

“well, we should probably finish up our homework now. then we can go downstairs and play mario kart or something.” He said, picking up his pencil, scrawling math equations onto his paper.

“Sounds g-great!” Alphys resumed her homework as well, taking a marshmallow from the plate.

———————-

“get dunked on!” Sans shouted, standing up from the couch and victory dancing next to Alphys.

“Y-you only won because o-of that stupid b-blue shell!” Alphys retorted, crossing her arms in mock offense.

That was mostly true. She would’ve gotten first place, if Sans hadn’t fired his blue shell at her. But that wasn’t the only reason. Throughout the whole race, Alphys had found herself not looking at the screen, but at Sans.

“well, i still won. and youuuuuu still lost!” He pressed a finger to her nose.

“Hmph!” Alphys pushed her claw at Sans’ “nose” in retaliation.

It didn’t really work, since there was nothing there to poke. So her claw just kind of...went into his nose.

Alphys froze.

_Shit shit shit shit._

“pfffff hahaha!” Sans doubled over in laughter, holding his non-existent sides.

Alphys started to giggle as well, until the pair were laughing uncontrollably on the couch, victory music still playing loudly from the T.V.

The laughter quieted down after a bit, and the two were left gasping for air, controllers put to the side.

Papyrus peeked from around the corner of the hallway, and snickered mischievously, eye sockets narrowed

“Now kiss! Kiss like the love birds you are!” Papyrus shouted, causing Sans and Alphys to jump nearly 3 feet in the air.

Sans’ face flushed a bright blue, and Alphys’ a scarlet red.

“i-i umm...w-we, uh!” Sans stuttered over his words.

“W-we d-d-don’t, ummm!” Alphys buried her face in her arms, trying to hide herself.

Gaster poked his head out as well, above Papyrus’. 

“You heard the boy, now smooch!” He made finger guns at Sans, winking.

“daaaaad!? not you too??” Sans’ face somehow grew brighter, and Alphys just squealed into her pink sweater.

“Come on Sans!” Papyrus spoke up. “It’s obvious you two are madly in love with each other!”

Gaster gave him a thumbs up.

“You’ve got this, kids!”

Alphys uncovered her face, glancing at Sans. To her surprise, Sans was looking at her too.

Not giving herself time to think, she presses her mouth against Sans’, giving him a quick kiss, before immediately pulling away, face even redder than before.

Sans makes a strange noise, reminding Alphys of when a computer breaks down. 

_Oh god I think I broke him._

“Wooo! First kiss!” Gaster cheered from the hallway.

“shut up!” Sans squealed.

———————-

“Ah, I will never forget that day! The day my brother and Alphys confessed their undying love for each other.” Papyrus sighed fondly.

“that’s not how it happened at all and you know it.”

“My memory says otherwise, Sans!” Gaster chuckled.

“S-sans? Can you c-come help m-me with Arial?” Alphys called from the kitchen.

“sure honey bunny. stay here kiddos.” Sans got up, leaving Eliza and Roman to play with their Uncle Papyrus and Grandpa Gaster.

**Author's Note:**

> We need some more Sans/Alphys fluff.


End file.
